1. Field of the Invention
The present invention relates to the evaluation of radiographic images. More particularly, the present invention relates to creation of X-ray images from X-ray radiographs, processing these X-ray images, and image storage.
2. Discussion of Background
A radiographic image is a photograph made with visible or infrared light, including X-ray photographs, thermographs or any radiographs made using forms of penetrating or reflected radiation directed through or reflected from a body or object having features, internal or external, not readily discernible from the exterior. The purpose of radiographic photography is to ascertain information about the features of or within that body. Examples of the types of features shown in radiographic photographs such as dental, chiropractic, orthopedic and industrial X-rays include bone, vertebrae and tooth structure, and weldments. A radiograph is evaluated by using it to extract information about such features for analysis, diagnosis, prognosis, or certification. Typically, an X-ray is evaluated by drawing lines on it with a pencil and ruler to determine the relationships among the various features it contains.
X-ray and other radiation sources have been in widespread use in a variety of medical and industrial applications for creating images on photographic film. In the past few years, several apparatuses have been developed for creating an image of the X-ray film so that they may be displayed on a cathode ray tube (CRT). Typically, the X-ray is scanned to produce an analog, serial signal that is fed to the CRT for display through a television-type raster pattern. The image may be processed to improve brightness and contrast; it may be placed side-by-side with another image, such as a patient's previous X-ray or an X-ray of a weld joint of known quality, for visual comparison.
Recent examples of X-ray or radiation evaluation or diagnostic apparatus are found in U.S. Pat. No. 5,086,392 issued to Nakajima, in U.S. Pat. No. 5,077,768 issued to Shigyo, et al, and in U.S. Pat. No. 5,038,369 issued to Nishiki. Nakajima's device scans and compares two images in the diagnosis of radiographs. Shigyo, et al. read and process radiographs, looking for and responding to detected faults in the image. Nishiki's apparatus relates to forming a better CRT image by removing the off-set signal that occurs when no radiation is being received from the signal when the radiation signal is being received.
However, there remains a need for a system for evaluating radiographs that is useful to dentists, chiropractors and other medical and industrial professionals for relatively routine X-ray photographs depicting the orientation of bones, teeth, internal characteristics of welds, and other distinct features where geometric considerations-important to the evaluation of the X-ray can be handled automatically.